Submission #973832

#	Time	Username	Problem	Language	Result	Execution time	Memory
973832		kl0989e	Guess the number (BOI20_guess)	C++17	100 / 100	1 ms	596 KiB

Guess

#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define fi first
#define se second
#define pb push_back
#define vi vector<int>
#define pi pair<int, int>
#define all(x) (x).begin(),(x).end()

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    int n;
    cin >> n;
    int l=1,r=n;
    int res;
    while (l<=r) {
        int m=l+(r-l)/2;
        cout << "? " << m << endl;
        cin >> res;
        if (res==0) {
            cout << "= " << m << endl;
            return 0;
        }
        else if (res==-1) {
            l=m+1;
        }
        else {
            r=m-1;
        }
    }
    cout << "= " << l << endl;
    return 0;
}

• Subtask 1: 29 / 29
• Subtask 2: 71 / 71